TW202132874A - A liquid crystal display - Google Patents

Abstract

A liquid crystal display is provided. The liquid crystal display comprises a liquid crystal display panel, and a color improvement film disposed on a light exit surface of the liquid crystal display panel. The color improvement film includes a substrate, a strip-shaped micro-prism layer, and a filling layer. The strip-shaped micro-prism layer has a plurality of strip-shaped micro-prisms arranged in a first direction, and each of the strip micro-prisms has at least one inclined light-guide surface, and the inclined light-guide surface has an included angle with a normal direction of a surface of the color improvement film on a cross section perpendicular to the first direction, wherein, the strip micro-prism layer has a first refractive index n1, the filling layer has a second refractive index n2, and the second refractive index n2 is greater the first refractive index n1. The liquid crystal display can improve the color-shift problem at side viewing angles without affecting the display quality of the front viewing angles.

Description

LCD Monitor

The present invention relates to a liquid crystal display, in particular to a liquid crystal display equipped with a color improving film that can improve the color deviation of the side viewing angle picture and the color saturation reduction problem.

With the trend toward larger sizes of LCD monitors, especially for applications such as televisions or spliced display walls, even if the user is viewing these LCD monitors at a front viewing angle, the color performance and the center of the large-size LCD monitor can still be found on the edge of the screen. The picture is inconsistent, let alone when the user is watching from the side view, the overall color deviation will be more serious. Although today's liquid crystal displays have excellent viewing angle characteristics, allowing users to view the displayed images in various viewing angle ranges, because the liquid crystal molecules themselves have different symmetry at different viewing angles, the vertical backlight and the oblique backlight pass through The liquid crystal layer of the liquid crystal display will have different light paths. Therefore, the image produced by the oblique backlight of a general liquid crystal display cannot have the better image quality as that produced by the vertical backlight, and it is particularly prone to screen whitening (color washout) and gray-scale inversion (gray-scale inversion) at the side viewing angle. ) Phenomenon or color deviation, resulting in images with low contrast or abnormal color performance.

In addition, since the gray scale change from the bright state to the dark state of the liquid crystal display is not linear, it is conventionally known to add various standard gamma curves such as Gamma 2.2, Gamma 1.8, etc. to the driving method to correct the input voltage and display. The relationship between the brightness level and the tone allows the human eye to recognize each gray level close to a linear performance, but this method cannot achieve the correction effect for every viewing angle, and the above method of adding a standard gamma curve is generally only for the light and dark gray levels at the positive viewing angle. The degree of change or gray-scale inversion phenomenon can be corrected and compensated. The color consistency of the display image of the front view and the side view cannot be improved, because the bright white image is mixed by the light of different color sub-pixels, such as general The liquid crystal display uses the red, green, and blue light generated by the white backlight to pass through the red, green and blue sub-pixels to be mixed into white light again. After the red, green, and blue sub-pixels of white light pass through the liquid crystal molecules, their mixed intensity ratio will still change due to the change in viewing angle, resulting in the same gray-scale brightness change but the color may still be biased, especially for human eyes such as portraits and skin colors. Color performance, even if the change curve of brightness and gray scale is calibrated consistent, if there is a slight color deviation, it is still quite easy to be noticed by the human eye.

The conventional method of compensating the viewing angle of the display also includes adding a diffuser film or diffractive film on the surface of the liquid crystal display panel to diffuse and transmit the front-view light to the side viewing angle. However, due to the trend of thinning, the increasingly thin optical film Insufficient diffusion path in the thickness direction makes it difficult to generate light with a sufficient diffusion angle. The diffusion angle can only be increased by adding diffusion particles, but these methods will inevitably affect the fineness of the displayed image. However, the method of changing the angle of the emitted light by the diffractive film, because the diffractive efficiencies of the diffractive film for different wavelengths are inconsistent, it is still impossible to perform the same correction for the lateral viewing angle color deviation of each wavelength transmitted to the liquid crystal display panel, and the diffraction is only It is suitable for strengthening the intensity of light at a specific angle, and the continuity of the distribution of light in each side viewing angle range is not good.

Therefore, the present invention discloses a liquid crystal display, which can maintain a color performance close to the front view range in the side viewing angle range, thereby improving the image quality.

在本發明之一實施態樣中，揭露一種液晶顯示器包括：一液晶顯示面板；以及一色彩改善膜，設置於該液晶顯示面板之出光面上，該色彩改善膜包括：一基板；一條狀微稜鏡層，具有一第一折射率n1，且包含複數個沿一第一方向延伸的條狀微稜鏡形成於該基板上，該第一方向與該液晶顯示面板之水平方向相交於一角度介於90°±25°之間，每一該些條狀微稜鏡具有至少一導光斜面，每一該些導光斜面於垂直該第一方向之截面上與該色彩改善膜膜面之法線方向成一夾角θ ，且於該色彩改善膜膜面上之投影寬度總和相對色彩改善膜整體寬度之占比係不小於20%且不大於30%；以及一填平層，具有一第二折射率n2，且該第二折射率n2大於該第一折射率n1，該填平層覆蓋並平坦化該條狀微稜鏡層，且設置於鄰近該液晶顯示面板側；其中，該液晶顯示器之側視角平均色彩偏移值∆u’v’係不大於0.01，該側視角平均色彩偏移值∆u’v’ 代表於水平方位下，側視角40°至60°時，相對正視角0°所測得各側視角之CIE76色座標距離差值∆u’v’ 之算術平均值。

In an embodiment of the present invention, a liquid crystal display is disclosed including: a liquid crystal display panel; and a color improvement film disposed on the light-emitting surface of the liquid crystal display panel, the color improvement film including: a substrate; The ridge layer has a first refractive index n1 and includes a plurality of strip-shaped ridges extending along a first direction formed on the substrate, and the first direction intersects the horizontal direction of the liquid crystal display panel at an angle Between 90°±25°, each of the strip-shaped micro prisms has at least one light guide slope, and each of the light guide slopes is on the cross section perpendicular to the first direction and the color improvement film surface The normal direction forms an angle θ , and the ratio of the sum of the projection width on the color improvement film surface to the overall width of the color improvement film is not less than 20% and not more than 30%; and a leveling layer with a second The refractive index n2, and the second refractive index n2 is greater than the first refractive index n1, the leveling layer covers and planarizes the strip-shaped microscopic layer, and is disposed adjacent to the liquid crystal display panel; wherein, the liquid crystal display The side viewing angle average color shift value ∆u'v' is not greater than 0.01, the side viewing angle average color shift value ∆u'v' represents the horizontal orientation, when the side viewing angle is 40° to 60°, the relative positive viewing angle is 0 °The arithmetic mean of the CIE76 color coordinate distance difference ∆u'v' of each side viewing angle measured.

In an embodiment of the present invention, the difference between the first refractive index n1 and the second refractive index n2 is not less than 0.1 and not more than 0.3.

In another embodiment of the present invention, the angle formed by each of the light guide slopes on the cross section perpendicular to the first direction and the normal direction of the color improving film surface is greater than 0° and less than 20°.

In another embodiment of the present invention, the projection width of each of the light guide slopes on the color improvement film surface on the cross section perpendicular to the first direction is between 0.015 μm and 3.5 μm.

In another embodiment of the present invention, the height of each of the stripe-shaped microfins is between 0.9 μm and 5 μm.

In another embodiment of the present invention, when the light guiding slopes of the strip-shaped micro ridges are adjacent to each other, they are directly connected or separated by a distance.

In another embodiment of the present invention, when the adjacent light guide slopes are separated by a distance, the distance is the shortest distance between the light guide slopes, and the distance is between 0.38 μm and 12.3 μm .

In another embodiment of the present invention, the distances between the light guide slopes are the same or different from each other.

In another embodiment of the present invention, the adjacent light guide slopes are symmetrical or asymmetrical.

In another embodiment of the present invention, the liquid crystal display further includes a functional coating formed on the surface of the substrate of the color improvement film, wherein the functional coating can be selected from hard coating, anti-reflection layer, and anti-glare One of or a combination of groups formed by layers.

The above content of the invention is intended to provide a simplified summary of the content of the disclosure, so that readers have a basic understanding of the content of the disclosure. This summary is not a complete summary of the present disclosure, and its intention is not to point out important/key elements of the embodiments of the present invention or to define the scope of the present invention. After referring to the following embodiments, those with ordinary knowledge in the technical field to which the present invention belongs can easily understand the basic spirit of the present invention, as well as the technical means and implementation modes adopted by the present invention.

In order to make the description of the disclosure of the present invention more detailed and complete, the following provides an illustrative description for the implementation aspects and specific embodiments of the present invention; this is not the only way to implement or use the specific embodiments of the present invention. The embodiments disclosed below can be combined or substituted with each other under beneficial circumstances, and other embodiments can also be added to an embodiment without further description or description.

In the following description, many specific details will be described in detail to enable the reader to fully understand the following embodiments. However, the embodiments of the present invention may be practiced without these specific details. In other cases, in order to simplify the drawings, well-known structures and devices are only schematically shown in the drawings.

首先，請一併參照圖1以及圖2，圖1所繪示的是根據本發明之一實施態樣所揭示的液晶顯示器的剖視圖，圖2所繪示的是根據本發明一實施態樣所揭示的液晶顯示器的色彩改善膜之條狀微稜鏡層表面結構立體透視圖。該液晶顯示器1包括：一液晶顯示面板2；以及一色彩改善膜3，設置於該液晶顯示面板2之出光面上，該色彩改善膜3包括：一基板31；一條狀微稜鏡層32，具有一第一折射率n1，且包含複數個沿一第一方向D1延伸的條狀微稜鏡321形成於該基板31上，該第一方向D1與該液晶顯示面板2之水平方向(即X軸方向)相交於一角度介於90°±25°之間，每一該些條狀微稜鏡321具有至少一導光斜面321a，每一該些導光斜面321a於垂直該第一方向D1之截面上與色彩改善膜3膜面之法線方向成一夾角θ ，且每一該些導光斜面321a於該色彩改善膜3膜面上之投影寬度w總和相對色彩改善膜3整體寬度之占比係不小於20%且不大於30%；以及一填平層33，具有一第二折射率n2，且該第二折射率n2大於該第一折射率n1，該填平層33覆蓋並平坦化該條狀微稜鏡層32，且設置於鄰近該液晶顯示面板2側；其中，該液晶顯示器1之側視角平均色彩偏移值∆u’v’係不大於0.01，該側視角平均色彩偏移值∆u’v’ 代表於水平方位下，側視角40°至60°時，相對正視角0°所測得各側視角之CIE76色座標距離差值∆u’v’ 之算術平均值。

First, please refer to FIGS. 1 and 2 together. FIG. 1 shows a cross-sectional view of a liquid crystal display according to an embodiment of the present invention, and FIG. 2 shows a cross-sectional view of a liquid crystal display according to an embodiment of the present invention. A three-dimensional perspective view of the surface structure of the strip-shaped micro-ribbed layer of the color improving film of the disclosed liquid crystal display. The liquid crystal display 1 includes: a liquid crystal display panel 2; and a color improvement film 3 disposed on the light-emitting surface of the liquid crystal display panel 2. The color improvement film 3 includes: a substrate 31; It has a first refractive index n1 and includes a plurality of strip-shaped micro ridges 321 extending along a first direction D1 formed on the substrate 31, the first direction D1 and the horizontal direction of the liquid crystal display panel 2 (ie X (Axis direction) intersect at an angle between 90°±25°, each of the strip-shaped micro ridges 321 has at least one light guide slope 321a, and each of the light guide slopes 321a is perpendicular to the first direction D1 The cross section forms an angle θ with the normal direction of the film surface of the color improvement film 3, and the sum of the projection width w of each of the light guide slopes 321a on the film surface of the color improvement film 3 accounts for the total width of the color improvement film 3 The ratio is not less than 20% and not more than 30%; and a leveling layer 33 has a second refractive index n2, and the second refractive index n2 is greater than the first refractive index n1, and the leveling layer 33 covers and is flat The stripe-shaped microscopic layer 32 is formed adjacent to the side of the liquid crystal display panel 2; wherein, the side viewing angle average color shift value ∆u'v' of the liquid crystal display 1 is not greater than 0.01, and the side viewing angle average color The offset value ∆u'v' represents the arithmetic mean of the CIE76 color coordinate distance difference ∆u'v' of each side angle of view measured when the side angle of view is 40° to 60° relative to the front angle of 0° in the horizontal orientation .

習知CIEXYZ三刺激值色座標系統由於不均勻性以致於無法正確表達人眼對亮度、明度與飽和度的色偏分辨的能力。在工業生產製造中有關色彩的產業，也常遇到需評估色彩偏差問題以維持色彩一致性。因此國際照明委員會CIE於1976年提出基於CIEXYZ色彩空間轉換而得之均勻色彩空間CIE76 (L*, u*, v*)與CIE76(L, a, b)。CIE76(L, a, b)通常用於印刷產業，CIE76 (L*, u*, v*)則因座標具備光線可加成性，而適用於彩色顯示器產業，因為彩色顯示器的明度L*通常為不同波長混色組成，例如紅光、綠光及藍光，因此明度L*改變時會連帶影響其顯示影像之色相及彩度，而改變其座標值(u’, v’)，故可藉由比較與參考點之色座標距離差值∆u’v’，以量化特定明度值下該顏色相對參考點之顏色偏差程度。

The conventional CIEXYZ tristimulus color coordinate system cannot correctly express the human eye's ability to distinguish the color shift of brightness, brightness and saturation due to its inhomogeneity. In the color industry in industrial manufacturing, it is often encountered that the color deviation needs to be evaluated in order to maintain color consistency. Therefore, the International Commission on Illumination CIE proposed in 1976 the uniform color space CIE76 (L*, u*, v*) and CIE76 (L, a, b) based on the CIEXYZ color space conversion. CIE76 (L, a, b) is usually used in the printing industry, and CIE76 (L*, u*, v*) is suitable for the color display industry because of the light additivity of the coordinates, because the brightness of the color display L* is usually It is composed of mixed colors of different wavelengths, such as red light, green light and blue light. Therefore, when the lightness L* changes, it will also affect the hue and chroma of the displayed image, and change its coordinate value (u', v'), so you can use Compare the color coordinate distance difference ∆u'v' with the reference point to quantify the color deviation degree of the color relative to the reference point under a specific lightness value.

The conventional liquid crystal display panel structure includes a backlight module, a liquid crystal cell, and a polarizing plate arranged on both sides of the liquid crystal cell. Generally, the width ratio of the horizontal direction of the liquid crystal display panel is larger than that of the vertical direction, so the horizontal direction covers a larger viewing angle range. In a liquid crystal display panel of a large size, especially when there are multiple users who need to watch at the same time, the demand for image quality within the viewing angle range covered by the horizontal direction is relatively greater than that for the vertical direction. Please also refer to FIG. 3, which is a schematic diagram of the principle of improving the image quality of the lateral viewing angle range of the color improving film of the liquid crystal display disclosed in an embodiment of the present invention. The strip-shaped micro-ribbons 321 of the strip-shaped micro-rib layer 32 extend along the first direction D1, and intersect the horizontal direction of the liquid crystal display panel 2 (that is, the X-axis direction) at an angle of 90°± When the angle is between 25°, the plurality of light guide slopes 321a of the strip-shaped micro ridges 321 can simultaneously use the total reflection effect and the Brewster angle for the light L1 and L2 emitted from the liquid crystal display panel 2. Polarization effect, the first large deflection of the light path can be performed without multiple scattering and refraction, reducing the light from the color improvement film 3 to the side viewing angle process, because the light of different wavelengths is at the interface of different refractive index Multiple deflection and splitting of light produce dispersion, which causes additional color shift effects on the liquid crystal display. Since the second refractive index n2 of the leveling layer 33 is greater than the first refractive index n1 of the striped micro-rib layer 32, it can be seen that the incident angle of the light L1 in the normal viewing angle range to the light guide slopes 321a is not less than that of (1) When the critical angle θ _c is obtained, the total reflection can be generated from the light guide slopes 321a with less loss of light intensity. And for light L2 that is not completely incident from the normal viewing angle, but still has a good color shift relative to the side viewing angle, when the incident angle to the light guide slopes 321a approaches the Brewster angle θ _B obtained from the relation (2), it is still Can produce reflected light in the Y-axis polarization direction. Since the light emitted from the polarizing plate (not shown) on the surface side of the liquid crystal display panel 2 is generally highly polarized, especially when the absorption axis of the polarizing plate on the surface side of the liquid crystal display panel 2 is in the X-axis direction, it can make Most of the light L2 emitted by the liquid crystal display panel 2 is the light component of the Y-axis polarization direction. Therefore, the horizontal direction of the liquid crystal display panel 2 intersects the first direction D1 of the striped micro ridges 321 at an angle of 90°± When the angle is between 25°, the color improvement film 3 can further have better reflection and light guiding efficiency toward a large angle. θ _c = sin ^-1 (n1/n2) (1) θ _B = tan ^-1 (n1/n2) (2)

In one embodiment of the present invention, the strip-shaped micro-ribbons layer 32 can be formed by first embossing a plurality of strip-shaped micro-ribbons 321 on the substrate 31 and a first curable resin (not shown) with a first refractive index n1 Shown), and then cured to obtain. Then, a second curable resin (not shown) having a second refractive index n2 is filled on the surface of the strip-shaped microscopic layer 32 and planarized to form the leveling layer 33, the first curable resin and the second The second curable resin can be a photocurable resin or a heat curable resin. The first refractive index n1 and the second refractive index n2 can be selectively between 1.4 and 1.7, so that the first refractive index n1 and the second refractive index The difference of n2 is not less than 0.1 and not more than 0.3, and the second refractive index n2 is greater than the first refractive index n1. The first curable resin and the second curable resin (not shown) can be, for example, acrylic resin, silicone resin, polyurethane resin, epoxy resin, or a combination thereof.

In an embodiment of the present invention, the material of the substrate 31 of the color improvement film 3 may be polyethylene terephthalate (PET), polycarbonate (PC), cellulose triacetate (TAC), polymethyl Methyl acrylate (PMMA), polyimide (PI) or cyclic olefin polymer (COP), and its thickness can range from 30 μm to 300 μm.

Please refer to FIGS. 1 and 4 together. FIG. 4 shows a cross-sectional view of a color improvement film disclosed according to an embodiment of the present invention. In an embodiment of the present invention, the striped micro prisms 321 The angle θ formed by the light guide inclined surface 321a on the section perpendicular to the first direction and the normal direction of the film surface of the color improvement film 3 is greater than 0° and less than 20°. By controlling the range of the included angle θ, The normal viewing angle light with lower color shift emitted by the liquid crystal display panel can appropriately pass through the incident angle range that meets the above critical angle θ _c and Brewster angle θ _B to generate enough reflected light to be transmitted to a larger range of side viewing angle. The ratio of the sum of the projection width w of each of the light guide slopes 321a of the strip-shaped micro-ribbon layer 32 on the film surface of the color improvement film 3 on the cross section perpendicular to the first direction relative to the overall width of the color improvement film 3 It is not less than 20% and not more than 30%, which can prevent the effective light guide area of the light guide slopes 321a from being insufficient or excessive, resulting in insufficient luminous flux after effective light guide, or reducing the brightness and contrast of the front viewing angle display excessive. Although the overall width of the color-improving film 3 is usually different depending on the size of the liquid crystal display panel to be used, it is not fixed, however, because the method of making the color-improving film 3 is usually micro-engraving, embossing, etc. to form a plurality of striped micro-fins The repeating unit of 321 is then spread over the entire surface of the color improvement film 3 to form a striped microscopic layer 32. Therefore, in one embodiment, the projection width of the light guide slopes 321a can be calculated The proportion of w in the repeating unit is to obtain the proportion of the sum of the projection width w of the light guide slopes 321a of the striped micro-ribbon layer 32 to the overall width of the color improving film 3. The projection width w of each light guide inclined surface 321a of each of the strip-shaped micro ridges 321 on the film surface of the color improvement film 3 on the cross section perpendicular to the first direction is between 0.015 μm and 3.5 μm . The height h of each of the strip-shaped micro ridges 321 is between 0.9 μm and 5 μm.

Please refer to FIGS. 4 and 5 together. FIG. 5 shows a cross-sectional view of a color improvement film disclosed according to another embodiment of the present invention. In another embodiment of the present invention, in the first direction In the upward direction, one side of each of the strip-shaped micro-beams 321 may have a light guide slope 321a, or both sides have a light-guiding slope 321a, and the light-guiding slopes 321a of the strip-shaped micro-beams 321 correspond to each other. The adjacent time is directly connected or separated by a gap g. When directly connected, it can form a triangular strip-shaped micro-rib 321 with only a top edge 321b or form a bottom end 321c between two adjacent strip-shaped micro-ribs 321. When the adjacent light guide slopes 321a are separated by a gap g, the gap g is defined as the shortest distance between the light guide slopes 321a, because the gap g is only used to adjust the light guide slopes 321a accordingly The ratio of the total projection width w to the overall width of the color improvement film 3 is suitable for and optimizing the side-view character deviation performance of various liquid crystal display panels. It cannot provide the light guide slopes 321a to greatly reflect the light toward the side viewing angle. Because of the light guiding effect, the gap g is not limited to the width of the top plane 321d or the bottom plane 321e of the individual strip-shaped micro-matrix 321, and the gap g is between 0.38 μm and 12.3 μm. In another embodiment of the present invention, the striped micro ridges 321 can be independently set to be all or partly the same depending on the pixel arrangement, pixel size, overall requirements or product design requirements of different liquid crystal display panels. Therefore, The adjacent light guiding inclined surfaces 321a may be symmetrical or asymmetrical, and the distance g between the light guiding inclined surfaces 321a may be the same or different from each other.

Please refer to FIG. 6, in another embodiment of the present invention, the liquid crystal display 11 further includes a functional coating 4 formed on the surface of the substrate 31 of the color improvement film 3, wherein the functional coating 4 can be freely hard Coating, anti-reflection layer, and anti-glare layer constitute one or a combination of the group.

The following examples are used to further illustrate the present invention, but the present invention is not limited thereto.

Example

Example 1

The liquid crystal display disclosed in the first embodiment uses the brand model of the liquid crystal display panel: BenQ 50JM700, and the color improvement film is superimposed on the display side polarizing plate of the liquid crystal display panel itself. The first refractive index n1 of the strip-shaped micro-ribbed layer of the color improvement film is 1.51, the second refractive index n2 of the leveling layer is 1.61, and the first direction D1 along which the strip-shaped micro-ribbed layers are arranged The angle of intersection with the horizontal direction of the liquid crystal display panel is 70°, and the ratio of the sum of the projected component width w of the light guide slopes of the strip-shaped microscopic layer on the color improvement film surface to the overall width of the color improvement film is 29.7%, the individual projection component width w is from 1.10μm to 1.34μm, the angle between each light guide slope of the striped microspheres and the normal line of the color improving film surface is 12.5° and 15° staggered For the asymmetrical design, the height of each of the striped micro-fins is set to 5μm.

Example 2

In the liquid crystal display disclosed in the second embodiment, the brand model of the liquid crystal display panel used is: SAMSUNG C32H711QEE, and the color improvement film is superimposed on the polarizing plate on the display side of the liquid crystal display panel itself. The first refractive index n1 of the strip-shaped micro-ribbed layer of the color improvement film is 1.51, the second refractive index n2 of the leveling layer is 1.61, and the first direction D1 along which the strip-shaped micro-ribbed layers are arranged The angle of intersection with the horizontal direction of the liquid crystal display panel is 75°, and the ratio of the sum of the projected component width w of the light guide slopes of the striped microscopic layer on the color improvement film surface to the overall width of the color improvement film is 20%, the individual projection component width w is 0.88μm to 1.34μm, the angle between each of the light guide slopes of the striped micro-beams and the normal line of the color improvement film surface is 10° and 15° staggered. , The height of each of the strip-shaped micro-fins is set to 5μm.

Comparative example

Comparative example 1

Comparative Example 1 uses the liquid crystal display panel disclosed in Example 1, but the color improving film of the present invention is not attached.

Comparative example 2

Comparative Example 2 uses the liquid crystal display panel disclosed in Example 2, but does not attach the color improving film of the present invention.

表一： 不同側視角之白畫面色座標距離差值∆u’v’

Please refer to Table 1 for reference. Table 1 is the CIE 76 obtained by measuring the above-mentioned embodiment and comparative example with the Autronic-Melcher Conoscope 80 in the horizontal viewing angle range of 0° to 80° and converted to the emission spectrum of the bright white screen (L*, u*, v*) color space coordinates (u',v'), and then the color coordinate distance difference ∆u'v' obtained by comparing the difference of the emission spectrum with the central front viewing angle 0°. Generally, liquid crystal display panels have been optimized for the color accuracy of the front viewing angle. Therefore, from the measurement data in Table 1, it can be seen that the liquid crystal display panel is not attached to the color improvement film of the present invention in Comparative Example 1, which is approaching the range of the front viewing angle. Within 0° to 30°, and the LCD panel is not attached to the color improvement film of the present invention in Comparative Example 2, within the range of 0° to 20° approaching the normal viewing angle, a smaller color coordinate distance difference can also be obtained , That is, ∆u'v' is less than 0.01, because when ∆u'v' is generally judged to be less than 0.01, it is difficult for human eyes to distinguish the degree of color deviation. However, as the side viewing angle becomes larger, for example, after the side viewing angle is greater than 40°, the ∆u'v' of Comparative Example 1 and Comparative Example 2 are gradually greater than 0.01, and the degree of color shift perceived by the human eye is also greater. However, the liquid crystal display in the first and second embodiments of the present invention can suppress the color shift by the color improvement film in the structure and reduce the color coordinate distance difference, so that the side viewing angle can be used in the whole range of 40° to 80° Obtained a lower ∆u'v' value than Comparative Example 1 and Comparative Example 2, especially for the color coordinate distance difference ∆u'v' and its arithmetic mean ∆u for a side viewing angle of 40° to 60°, which is more likely to be used 'v' are all less than 0.01, maintaining the degree of color deviation that is not easy for the human eye to distinguish, and approaching the normal viewing angle range of 0° to 30°. Because of the high light guide efficiency, there is no loss of too much front-view light, which makes the color coordinate distance difference. ∆u'v' is still maintained at less than 0.01. Therefore, the liquid crystal display of the present invention can obtain nearly uniform color deviation in the range of 40° to 60° from the front viewing angle to the side viewing angle, thereby improving the display image quality and consistency.

Table 1: The distance difference between the white screen color coordinates of different side viewing angles ∆u'v'

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be subject to the definition of the attached patent application scope.

1, 11: LCD display 2: LCD panel 3: Color improvement film 31: substrate 32: Striped micro-layer 321: Striped Micro-snake 321a: light guide slope 321b: Top corners 321c: bottom 321d: top plane 321e: bottom plane 33: Filling layer 4: Functional coating D1: First direction w: projection width h: height θ: included angle g: spacing L1, L2: light

FIG. 1 shows a cross-sectional view of a liquid crystal display according to an embodiment of the present invention.

FIG. 2 is a three-dimensional perspective view of the surface structure of the color improving film disclosed according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing the principle of the color improving film of the liquid crystal display disclosed according to an embodiment of the present invention for improving the image quality in the side viewing angle range.

FIG. 4 illustrates a cross-sectional view of the color improvement film disclosed according to an embodiment of the present invention.

FIG. 5 illustrates a cross-sectional view of the color improvement film disclosed according to another embodiment of the present invention.

FIG. 6 shows a cross-sectional view of a liquid crystal display according to another embodiment of the present invention.

1: LCD display

2: LCD panel

3: Color improvement film

31: substrate

32: Striped micro-layer

321: Striped Micro-snake

321a: light guide slope

33: Filling layer

w: projection width

θ: included angle

Claims (10)

A liquid crystal display includes: a liquid crystal display panel; and a color improvement film disposed on the light-emitting surface of the liquid crystal display panel, the color improvement film including: a substrate; n1, and includes a plurality of stripe-shaped micro ridges extending along a first direction formed on the substrate, and the first direction intersects the horizontal direction of the liquid crystal display panel at an angle between 90°±25°, Each of the strip-shaped micro ridges has at least one light guide slope, and each of the light guide slopes forms an included angle θ with the normal direction of the color improvement film surface on the cross section perpendicular to the first direction, and The ratio of the sum of the projection width on the film surface of the color improvement film to the overall width of the color improvement film is not less than 20% and not more than 30%; and a leveling layer has a second refractive index n2, and the second refractive index n2 is greater than the first refractive index n1, the leveling layer covers and planarizes the stripe-shaped microscopic layer, and is arranged on the side adjacent to the liquid crystal display panel;

Wherein, the average color shift value Δu'v' of the side viewing angle of the liquid crystal display is not greater than 0.01, and the average color shift value Δu'v' of the side viewing angle represents in the horizontal orientation, when the side viewing angle is 40° to 60° , The arithmetic mean of the CIE76 color coordinate distance difference ∆u'v' of each side viewing angle measured relative to the front viewing angle 0°. The liquid crystal display described in claim 1, wherein the difference between n1 and n2 is not less than 0.1 and not more than 0.3. The liquid crystal display according to claim 1, wherein the included angle θ formed by each of the light guide slopes on the cross section perpendicular to the first direction and the normal direction of the color improving film surface is greater than 0° and less than 20°. The liquid crystal display according to claim 1, wherein the projection width of each of the light guide slopes on the color improvement film surface on the cross section perpendicular to the first direction is between 0.015 μm and 3.5 μm. The liquid crystal display according to claim 1, wherein the height of each of the striped micro ridges is between 0.9 μm and 5 μm. The liquid crystal display according to claim 1, wherein the light guide slopes of the strip-shaped micro ridges are directly connected or separated by a distance when they are adjacent. The liquid crystal display according to claim 6, wherein when the adjacent light guide slopes are separated by a distance, the distance is the shortest distance between the light guide slopes, and the distance is between 0.38 μm and 12.3 μm between. The liquid crystal display according to claim 6, wherein the adjacent light guide slopes are symmetrical or asymmetrical. The liquid crystal display according to claim 6, wherein the distances between the light guide slopes are the same or different from each other. The liquid crystal display according to claim 1, further comprising a functional coating formed on the surface of the substrate of the color improvement film, wherein the functional coating can be selected from a hard coating, an anti-reflection layer, and an anti-glare layer. One or a combination of the group.

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